With the energy depletion and environmental pollution worsening gradually, various new-type combustion technologies emerge, and the dual-fuel combustion technology appears. With the development of electronic technology and the improvement of internal combustion engine design, the diesel technology, gasoline technology and dual-fuel engine technologies such as gasoline/natural gas dual-fuel engine, natural gas /diesel dual-fuel engine, gasoline/diesel dual-fuel engine, biodiesel/diesel dual-fuel engine have been developed rapidly.
Since the cylinder combustion status of the internal combustion engine affects the overall performance of the engine directly, organizing injection reasonably and further controlling cylinder combustion are the most direct and effective way to improve the engine performance. Currently, the fuel injection system applied to the dual-fuel engine is mostly the dual-injector system, that is, two injectors are mounted in three different ways to realize different methods of injection: The first way is that a fuel injector is installed on the intake manifold, while another one is installed on the cylinder head to make one fuel injected on the intake manifold and another injected in cylinder. The second way is that two injectors are all installed on the intake manifold, to make both fuel injected on the intake manifold. The third way is that two injectors are all installed on the cylinder head, to make both fuel injected in cylinder.
The first two of the three injection ways can be achieved by modifying the existing single fuel injector engine, but they impose a specific restriction on the physical characteristics of the fuel, that is, the fuel injected external cylinder has a high volatility.
The third way has broad development prospects as there is no restriction on the physical properties of the fuel. But it complicates the structure of the cylinder head, making difficult to modify the existing single injector engine and also increasing the manufacturing cost.
At present, there are some dual-channel injectors in the market, but they are very complex and the installation of them needs to change the cylinder head.